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Some notes regarding analog - this seems like it's defined in analog.c, static const uint8_t pin2sc1a, which is an array where the index is the pin number and the stored value refers to the ADC channel number. For...

When you call pinMode, portConfigRegister is called, which is defined in pins_arduino.h. This is simply calling digital_pin_bitband_and_config_table_struct digital_pin_to_info_PGM from pins_teensy.c with the index of...

Overview:
I'm working on a Teensy 3.6 project where I would like to create an analog signal conditioning circuit that can be flexibly configured by the Teensy to work with a variety of input signals. I'm anticipating...

Thanks Mike,
For the MPU9250 library, did you try both SPI and I2C? I just tried it with I2C and I'm not getting communication with Wire (I2C1, pins 18/19) and Wire3 (pins 16/17) is undefined.
EDIT: nevermind, pins...

I dug into this more this morning. If I apply regulated 3.3V power to VIN, the board works. This board was designed to rely on the internal regulator in the MK66 microcontroller; however, the Teensy 3.6 does not use...

I'm trying to transfer data very quickly between 2 Teensy 3.6's. I'm trying to use SPI, since that should be the fastest method. I'm using the following config for my SPI master Teensy 3.6:
* CS: 10
* MOSI: 11
*...

Yes, NED. I can recommend Dan Simon's book for EKF. There are a few papers that mention the EKF presented here at a high level, but none (to my knowledge) go into the specifics. It's a very straightforward filter,...

Hi Bruce, sorry I've been down with an upper respiratory bug for the past few weeks. And now I'm playing catch up.
I haven't had a chance to track down exactly what I was experimenting with. The MPU9250 library I...

Honestly, for heading and tilt in walking conditions the AHRS might not be appropriate - I'm not sure you would see enough dynamic motion in that context. I would consider implementing a tilt-compass, which is what...

No, this is a pretty oft asked subject. I suggest searching the forums for similar questions regarding updating firmware over different protocols. The only supported method is via USB and any other approach will require...

One final suggestion - if you are going to be doing floating point math on the second Teensy, give the 3.6 a look. It has a hardware FPU and can give you very fast calculations if you remember to use the float version...

If wire lengths between the two Teensys are small, my preference would be I2C with the Teensy reading the ADC's set up as I2C Master. You could transfer up to 101 kBytes/s if you overclock your Teensy 3.2's to 120MHz:...

Read this thread, it discusses an ADC library for Teensy that enables synchronous sampling of both channels:
https://forum.pjrc.com/threads/25532-ADC-library-update-now-with-support-for-Teensy-3-1?highlight=pevide+adc...

I'm working on debugging this hardware design. Two boards have been manufactured with the same symptoms:
1. The bootloader shows up correctly when plugged into USB
2. The teensy loader loads the program and reboots,...

So, theoretically speaking, if we run Teensy 3.6 at 240 MHz, we can compute that a single tick would be 4.1667 ns. If we used the newest overclocking scheme, which can get us to 256 MHz, that drops to 3.9 ns per tick.
...

You should be able to get the timer working - IIRC, using the Teensy 3.6 clock and counting cycles will get you 4 ns precision at 240 MHz. I've thought about creating a nanos() library, similar in functionality to...

I think the approach is to extend the pin numbering (https://forum.pjrc.com/threads/54114-Extended-Pin-Numbering), with a forked Teensy core, and then let the community add support for various ports and libraries from...

Neat project! Regarding the Teensy 3.6 "Pro", see this:
https://forum.pjrc.com/threads/53225-Teensy-3-6-quot-Pro-quot-Feedback
I've got some initial boards and am in the process of debugging. Not sure how long it...

Mike asked a similar question and the honest answer is I don't remember, but should be working with it again soonish and find out why:
https://github.com/bolderflight/uNavINS/issues/3
I would guess that you should...

The magnetometer will not show up on an I2C scan unless you specifically set the MPU-9250 into bypass mode (register 55, bit 1).
Edit: mis-read post, looks like you have it in bypass mode to pick it up at 400 kHz....

Often I use analogWrite rather than the servo library. Noticed that the servo library would issue commands round robin, which old receivers would also do, but means a lot more delay if you are using lots of servos....

To me, I think the focus should be on users getting expected behaviour rather than performance. I think this is doubly important with Arduino users, who may not be digging into compiler flags. There are use cases where...

As far as I'm aware, there is not a good suffix to add to specify a double, only 'f' to specify a float. So, it seems to me like constants that are not specified would need to be treated as doubles on Teensy 4.0 rather...

Long term, yes, I would like to incorporate air data into the INS estimate when available. I'm not sure what the effect would be on output accuracy, but, it would help arrest drift in cases where GPS is unavailable for...

The cool thing is that nanopb is protobuffers. So I'll use nanopb on Teensy 3.6, regular protobuf on a BeagleBone Black or a desktop (which can transpile to C++ code, Node.js, Rust, etc). It all works together. You can...

Not yet, but it's on my long term "to do" list. My goal is to incorporate it by overloading the class declaration, like:
* Serial: UBLOX ubx(Serial1, 115200);
* I2C: UBLOX ubx(Wire, 0x48);
The rest of the methods...

Our timing is good and we haven't had issues missing frames. I'm moving baseline components to the FMU because:
1. If a research software component completely locks up the processor, we still have auto control laws to...

Ha, Curt works at the UAS Lab. We're actually using JSBSim at the moment - in the past we've used an in house Simulink based simulation and we may move back to an in house sim at some point in the future.
Yes, we use...

One of the things that I did with UMN is migrate some of the RAPTRS v2 changes into v1. So, what you see online at https://github.com/bolderflight/RAPTRS is actually v1 with a bunch of improvements. I need to find a...